78 BRITISH SERPENTS. 



the slough has been cast. They are the same in 

 general character in the female, but not so brilliant. 

 At the back of the head, which is flattened, there are 

 two narrow dark or black bands, converging to a 

 point on the top of the skull. These two dark bands 

 may or may not join at the point to which they 

 converge ; as a rule, they do not quite join. They 

 form the well-known characteristic V-shaped mark, 

 the point of the V being towards the snout of the 

 adder. But this V-mark, although always present in 

 adders, shows endless variety. As I write, there are 

 a number of preserved adders on the table before 

 me, and on looking closely at them seriatim, it is 

 noticeable that the mark is slightly different in each 

 specimen — very different, indeed, in some from others. 

 The following drawing (natural size) shows some of 

 these variations. The figures under each drawing 

 refer to the length of the adder to which the marking 

 belongs, measured in inches. These specimens were 

 taken haphazard out of my collection, and they 

 show well that the V-shaped mark is a very varying 

 one. Immediately behind the V the adder is of a 

 bright yellow colour very often, showing up the 

 dark markings more prominently. Then, proceeding 

 in the description along the back, the zigzag black 

 line is noted, the first patch of which is shown in 

 the drawings. This first patch also varies greatly 

 in shape, but as it goes along the back it becomes 

 more regular. This line of markings is continued 



